Why You Should Use GTK+
If you are looking for a “development environment” for the Linux platform, you will have several to choose from. GTK+ is one of the leaders for GUI development on the Linux platform mainly for the following reasons:
It is simple. The complexity behind drawing widgets and handling events has been hidden from you, so you can focus on your application’s functionality.
It is extensible. You can create your own widgets.
It is “open source.” You can read and modify the code.
It is portable to other operating systems that support the X-Window system. (Ports are also underway to MS Windows and BeOS, among others. However, as of this writing, they should still be considered in the early stages of development and used only with caution.) ...